5 Stars worth watching

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20 Responses to “5 Stars worth watching”

  1. Anonymous says:

    It is a shame that Carl Sagan is not around. This is all so incredibly exciting and so much of my interest in this was fueled by him that when I read about exo-planetology or life elsewhere I think of him.

  2. Cochituate says:

    VERY interesting article. These are close enough that an optical scope in orbit will likely pick up disks of any planets that are there. My interest is how the angular momentum data matches up with what is observed, to give a confirmation of what we think is working with suns that are further away.

  3. Tatsuma says:

    How come if we can see Alpha Centauri as a double star system there aren’t any other stars showing up in the photo? NOT trying to be a conspiracist or anything, just curious.

    • Anonymous says:

      @Tatsuma – I can see two stars in that photo. They’re pretty close together but there are definitely two bright objects sitting on the edge of the ring.

    • Lee Billings says:

      Both Alpha Centauri A and B are some of the brightest stars in the sky, because they’re relatively large and very close to us. The only stars that outshine them in our skies, other than the Sun, are all *huge* stars, like Canopus, Sirius, and Arcturus.

      So it doesn’t really take a long exposure to get a good picture of them. I’m guessing the exposure was too short for other, fainter stars to show up.

      • Anonymous says:

        Sirius isn’t that big as stars go, and it’s not that far away – less than three times the distance to Alpha Centauri.

  4. imag says:

    Great post (again!).

    I do have to say: it might seem in astronomy circles like cosmology is taking up the limelight. From my view outside though, cosmology is a much-needed promotion of the value of considering the stars, and is entirely complimentary to astronomy. In other words, more consideration of cosmology brings more consideration of astronomy, from what I see.

    And almost anything that gets people thinking of something larger than the latest celebrity news is a good thing in my book.

    • Lee Billings says:

      I agree for the most part. Cosmology asks lots of deeply fascinating and profoundly important questions, and knowing their answers gives us a better sense of our place in the universe, just like other subdisciplines of astronomy/astrophysics.

      But given the extremity of scale that cosmology operates on, “our place in the universe” shrinks to a rather indistinguishable dot. What I like about the search for habitable planets is that it expands that dot of familiarity outward into our entire galaxy and beyond. The stars would perhaps seem less cold and distant if we knew we weren’t alone. And that’s worth considering when it comes to the necessary evil of prioritizing funding.

  5. Anonymous says:

    …and if you’d like to get involved in the hunt for exoplanets then there’s a citizen science project using the Kepler data: http://www.planethunters.org

    They’ve already found planets that the Kepler team have missed!

  6. Sam125 says:

    From reading the abstract from the Cornell library link, is the probability of finding a potentially habitable planet really 10%? That seems like an incredibly high value.

  7. VagabondAstronomer says:

    Alpha Centauri.
    Funny you should throw that one in the list. My own understanding is that if there are planets they’d be small “terrestrial” worlds sticking close to their parent star. Anything 5 AU and out would be subject to the tug from the companion star and possibly ejected. As much as I’d love to see a stable planetary system there, I have my doubts.
    But I really want to be proven wrong on that.

    • Lee Billings says:

      Yep, you’re right. But from an Earth-like/habitability perspective, we aren’t really that interested in anything orbiting several AU out from either Alpha Centauri A or B. We’re interested in the closer-in terrestrial planets that might be there.

      I talk about this a lot more in the 2009 feature story (http://seedmagazine.com/content/print/the_long_shot/). One of the big sticking points is that, while stable orbits do exist in the habitable zone, it’s unclear how exactly planet formation would proceed in the first place around this binary-star pair. So there is a chance that Alpha Centauri is orbited only by sand and dust.

  8. TimDrew says:

    Good post, as usual!

    As for stars I’d add to the list; I’ve always had a good feeling about Eta Casseiopeiae (sure, it’s a binary system, but still)… dunno why.

  9. spincycle says:

    One of my old professors has worked on a starshade design for a space-based telescope that could resolve significant details in such a search of nearby star systems. It’ll likely never see funding, but it, and the many other designs for both imaging and spectroscopy show that there are plenty of opportunities for doing good science even if we can’t investigate directly.

  10. Anonymous says:

    Aside from Alpha Centauri (which I remember from my amateur astronomy days), are any of the stars on the list visible to the naked eye?

    I’d love to be able to go out in my backyard and look at a star that we know has a planet around it. That’s something which would fire my imagination and maybe rekindle my long-dormant interest in astronomy.

    Until that point though, yeah, cosmology is way more interesting to me and I absolutely see why it gets more attention.

    • chenille says:

      Here are some nice bright stars that have known planets, and are easy to find:
      1. Fomalhaut
      2. Pollux
      3. Gamma Cephei
      4. Gamma Leonis
      5. Epsilon Tauri
      These are all giant planets, not the little habitable worlds Lee is excited about. But I’d recommend them if you just want to see another system with your own eyes.

    • Lee Billings says:

      Hi Anon,

      Lots of known planet-bearing stars are visible the the naked eye! And, if planets are as prevalent as I think they are, when you look up at the night sky and see a star, chances are there’s something “planetary” around it, albeit perhaps only quite small. But back to the ones we know about for sure… a preponderance of them are most easily seen from the southern hemisphere, it seems, because that’s where a lot of the best observatory sites and equipment are located.

  11. mrrx says:

    No argument with the first three. What about replacing the last two, why not :

    Epsilon Eridani, the closest star with a confirmed planet ? It’s only 10ly away. Anything that close just feels like it should generate important information.

    Or Gliese 876, with four planets, and about 15ly away ? The discoveries keep popping up on this one, the longer it’s studied.

    • chenille says:

      Plus Epsilon Eridani has two asteroid belts and a thick outer disk, and based on them probably has at least two more planets we haven’t confirmed.

  12. Nathaniel says:

    Great post. I think a focus on seeing the details of nearby planets would be a great thing, even if we don’t discover a habitable one. We live in a universe full of planets and moons. It seems that there’s a huge amount of variety in what these places can be like, but we have only a limited number of examples in our Solar system. The more specifics we can find out about the worlds nearby, the better we can imagine what the rest of the universe is like.

    One thing I’d really love to see is spectroscopy data from exoplanets that would allow detailed analysis of their atmospheres’ composition – I’m certain that kind of data would throw up many fascinating surprises and would give us a far better idea of what planets in general are like. I don’t know how hard it is to get that kind of data, but I bet it’s much easier if the planet is nearby.

    In particular, as was originally pointed out by James Lovelock, the atmosphere of the Earth with its biosphere is far from chemical equilibrium, unlike the other worlds in the Solar system. If we could detect that another planet’s atmosphere was far from equilibrium we would know that something very interesting is going on, even if the planet is not in the region generally recognised as “habitable” by life-as-we-know-it. It would suggest (though not prove) that life or something like it can exist in a form chemically very different to that of Earth. To me that’s the kind of surprise we should be looking for.

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